Drawbench



June 1, 19 3- E; KNUDSEN EI'AL DRAW BENCH Filed July 23, 1941 4Sheets-Sheet l lllllllllllllllLlllll 0? ATTORNEY June 1,1943. 7 E,KNUDSEN ETAL 2,320,739

DRAW BENCH Filed July 25, 1941 4 She ets-Sheet 2 l VENTORS 4 M My.

T 6/1? ATTORNEY- June 1, 1943. SEN HAL 2,320,739

, DRAW BENCH Filed July 25, 1941 4 Sheets-Sheet 3 I VEN CR3 7' 7?ATTORNEY June 1, 1943.

E. KNUDSEN ErAL DRAW BENCH Filed July'23, 1941 4. Sheets-Sheet 4'MVEHTQRS Evy 9 5 T/ HRATTQRNEY means comprises a downwardly and ingdrawings in which Patented June- 1,

nitawnENcn Earl Knudsen and Howard said Talbot assigno ing- & FoundryCom other.

n. Talbot, Pittsburgh,

1' to United Engineerpany, Pittsburgh, Pa., a v

corporation of Pennsylvania Application July 23, 1941, Serial No.403,678 r 19 Claims.

This invention relates to draw benches, and more particularly to thosedesigned for-reducing or shaping a plurality of elongated blanks such astubes, rods, bars or other shapes simultaneously;

It is among the objects of this invention to provide a draw bench whichutilizes independent blank-gripping carriages, which automaticallyreturns to the dies carriages released from blanks that have been drawnthrough the dies, which is rapid in operation, in which the variousblanks do not interfere with each other, and in which undue strain isnot placed on the apparatus.

gripping portion Referring to Figs. 1, 2 and 3 of the drawings, 1 aplurality of dies l are mounted in the upright enlarged horizontal viewof the modifiedblankof the carriage.

front end of a support 2 that extends forward over an open pit from afoundation. Starting at a point spaced a short distance in front of theIn accordance with this invention each of a. plurality of independentblank-gripping carriages is successively" disposed in frontpf a die,such as a tube-reducing die, where: it can be clamped to the end of ablank projecting thmugh the die. Means is provided for moving thecarriage and its gripped blank forward until the blankleaves the diewhereupon the carriage is released from the blank which falls into atrough or the like. The carriage is then returned to a position adjacentthe die, is moved'to blank-gripping position in front of the die. Mostsuitably each carriage carries a plurality of pairs of clamping jaws forgripping a plurality of blanks simultaneously. These jaws are atdifferent levels or positions on the different carriages so that theblanks first carriage will not interfere with thecarriage behind it.Preferably the carriage-retuming rearwardly inclined track onto whichthe carriage rolls after being released from the blanks it'wasdrawing.The carriage then is raised from the rear end of the track back toblankripplng position in front of the dies by suitable elevatingmechanism.

The invention is illustrated in the accompany- Fig. 1 is a side view ofour apparatus; Fig. 2is an enlarged fragmentary plan view of the die-endof the apparatus; Fig. 3 is a vertical longitudinal section through oneof the carriages in front of the dies; Fig. 4. is an end view of acarriagein front of the dies; Fig. 5 is a vertical transverse sectionthrough the top of the elevator; Fig. of the carriages that draws metalblanks from the top pair of dies; Fig. 7 is a vertical section of themain track taken on the line VIIVII of Fig. 2; Fig. 8 is an aontalsection of a blankripping portion of a carriage; Fig. 9 is a verticalsection taken on the line IX-IX of Fig. 8; Fig. 10 is a section takenvertically of a modified carriage; and Fig. 11 is an being drawn by thefiisanendviewofone' dies and slightly below them is a horizontal track 3having channel-like sides-that face each other and form rails (Fig. 7).

track is supported by the bottom of the track on which it slides.

its ends, and the forward sprocket 6, driven in any suitable manner.

preferably below it, from which it pivotally mounted on a lugs 22 (Fig.4) integral with the carriage andhaving a longitudinal slot 21 60.enlarged fragmentary hori-.

The track 3 is adapted to recelveand guide a tube-gripping carriage I ihaving vertical wheels l2 at each end that travel in'the track channels,

and horizontal wheels ii that roll against the upper flanges of thechannels to center the carriage in the track as shown in Fig. 4. Thecarriage is provided on in line with one of the dies. Each of theseopenings tapers toward its rear'end and slidably receives and guidesv apair of jaws I! (Fig. 2) the front ends of which are loosely mounted'inopenings in a. cross arm la. The cross arm is also provided. with avertical opening through which an upright lever 2i loosely extends. Thelever is horizontal axis in bearextends down into the carriage whereacross pin 23 spans its bifurcated lower end (Fig. 3). when jaws I! arenot gripping a tube the upper end of l the lever is swung forward ashort distance by means of a counterweighted arm 24' attached thereto. 5v

Slidably mounted inside of the carriage and projecting from its frontend is a long hook 26 ceives cross pin 23 at the lower end of the lever,as shown in'Fig. 3. When the carriage is in position ready to griptubes. it is'supported in front of the dies and in line with the track 3by an elevator 29 that I 4 and between the jaws in openings ii of thathead. The topof lever 2| is then swung rearwardly manually to force thejaws farther back in the wedge-shaped openings lit-whereby to se- Theupper strand of an endless chain 4 that extends lengthwise 'oi'the Thechain extends around sprockets 5 and 6 joumaled below the track near topwith a cross head 14 having a horizontal opening it through each .end

therein that rerear end of the j. will be described later. When in thisposition tubes II which have substantially the same Asshown time fluidunder pressure is supplied to a cylinder 32, mounted on the foundationbeneath the die support 2, so as to move. forward a plunger a thatengages the rear endof hook 26 as shown in Fig. 3v and pushes it forwardwhile the carriage. is retained on the elevator by a latch 2.

is formed for drawing tubes through the upper pair of dies. To permittubes to be drawn through all of the diesat the same time the upper pairof dies are located between the lower pair,- and the cross head and armof the carriage of Fig. 6 are short 'enough to fit between tubes beingdrawnfrom the lower dies. Consequently, two carriages can be pulledalong track 1 at the same time by the chain 4. As the carriages arespaced along the chain the strain is not all concentrated at one pointand the shock on the apparatus caused by carriage is pulled out ofengagement with latch 2|. In its forward position the rear end of hookslot 21 pulls against cross pin 23 at the bottom of the lever andthereby tends to force jaws I! more tightly against the tubes. The chainpulls the carriage and the tubes gripped by it forward along track 3.whereby the tubes are drawn through the dies and their diameter reducedaccordingly.

Before the carriage reaches the front end of the chain the rear ends ofthe tubes leave the dies. This materially reduces the backwardpull onthecarriage so that as soon as the chain has disengaged itself from hook 26the counterweighted arm 24' swings the upper end of lever 2| forward torelease the jaws from the tubes. The released tubes drop down ontransverse guard members or skids 3' from which they roll into cradles31 at the opposite sides of the track as shown in Fig. 7. Each of theseskids is'in the form of an arm pivoted at the side of the track andextending upwardly toward the center of the track. The skids arenormally held in this position by springs 35 so that-after they havebeen pushed aside by the carriage as it moves along the track they willswingbacl: into position across the track. I

After hook it has been released from the endless chain the carriage ispushed forward onto the inclined front end of the track by theengagement of the. chain with a dog 38 pivoted to thebottom of thecarriage as shown in Fig; 3. The carriage carriages periodicallyengaging and leaving the chain is minimized. 4

Fig. -1 shows a carriage being pulled forward by the chain and drawingtubes through the top pair of dies, while resting onelevator II in frontof the dies is another carriage that has just been attached to tubesprojecting from the lower pair of dies inreadiness to hook onto thechain also. The carriage that drew the preceding set of tubes from thelower dies has released them and is shown rolling down the transfertrack ll. The carriage that drew the preceding set, of tubes from theupper dies is shown on return track it where its travel back to theelevator has been ar- Y rested temporarily by escapement 41. As soon asthe carriage shownon the elevator in front of the dies has been pulledonto track 3, the eleva- -tor will be lowered for receiving the lowercarriage from the escapement and for then raising it into tube-grippingposition. e

In the embodiment of the invention shown in Figs. 8'and 9 the jaws I!slide in a cross hesfd 56 on both sides of an opening 51 thatds open atits top as well as at its ends. with this construction the front end ofa tube can be projected from a die before the carriage is elevated, andthen the with its projecting-hook rolls down onto an inclined transfertrack .ll that is pivoted at its front end on a horizontal axis in abearing 42.

. This track is held in its upper position by means of a pivotallymounted fluid pressure cylinder 43. and is provided near its front endwith a bumper l! to stop the carriage and to drive hook 28 back into it.The cylinder 43 is also used to lower the upper-or rear endof thetransfer track into line with the front end of a rearwardlyanddownwardly extending return track II so that the carriage canrollbackwardly by gravity from the transfer track onto the return trackuntil it is stopped by an escapement 41 actuated by a fluid pressurecylinder ll. when this escapement is actuated to release a carriage thelatter mils on down the return track and onto the top of the elevator 29which, in the meantime has been loweredsothatitwillbeinline'withtherearend' of the return track. As shown in Figs. 3 and 5 the t pof this elevator is provided with channel-' like rails II that can bealigned either with the return track or with the main track. At the rearend of each elevator rafl there is a spring biased stop I! which arreststhe rearward movement of the carriage. The elevator is raised andlowered by a vertical rod II connected to a piston in a fluid pressure.cylinder I4 standing below the elevator. j i

in Figs. and 4 there are two levels of dies I, although there could bemore. The carriage I I shown in these two figures draws tubes throughthe lower level, while the carriage shown carriage raised to cause thejaws to move up opposite sides of the tube to gripping position.

The modified form, of carriage Ila is adapted to be received in tracks 3in a fashion similar to that with respect to carriage II describedheretofore. Carriage Ila is provided with vertical wheels I20 at eachend that travel in the track channels and horizontal wheels, not shown,similar to those of carriage II which roll against the upper flanges ofthe channels to center the carriage in the track. The carriage isprovided on top with a crosshead lla hav'ing a horizontal openingthrough each end'in line with the dies.

and slidably receives and guides a pair of jaws Ila, the front ends ofwhich are provided with hooks 42a for engaging the recessed portion ofmembers a. The members "a are secured for sliding movement on theprojection a of cross-' head Ila by means of studs IOa passing throughthe outer edge of the projecting portion and threaded into a boss at thelower. portion of member 43a positioned in the slot a. A spring 22aencircling the stud issecured in place by means of nut Ila threaded onthe opposite end of the stud, the springs being compressed between thenut and projection Ila at the front end of slot as. Engaging the outeredges of members "a are the outwardly projecting arms of a pivotallymounted lever "a. This lever is secured for piv- .otal movement at itsmid-section by a bolt Ila passing therethrough and into a member "aslidabiv mounted on ways provided on the proiecting portion of crossheadIla. Pinned at one end to a boa a of member "a is a strut flahavingpinned at its opposite end a lever a. This lever, pivotally mounted at"a on the pis- 1 r s 7; ton rod in, is provided with a gripping-jaw ad-2,320,739 lusting handle fla at oneend and a pin 2311 at the other whichpasses through a longitudinally extending slot 21d of hookffia.

' Secured to the piston red 4911 is a piston 38a received in cylinder39a firmly mounted on the framer A bolt ila'is passed through aclearance hole drilled in the bottom portion of cross head Ila andthreaded into the end .of the piston rod 49a encircled by -a spring5211. A needle valve a for bleeding the compressed air from the cylinderanda. check valve 40a for permitting air to be drawn into the cylinderwhen the piston is returned to its normal idle position are incommunication'with the cylinder at the head end thereof.

In order to cause the hook 26a to engage one of the links of thecontinuousmoving chain 4, a piston provided with a rod 33a is actuatedto engage the hook 28a to push it forward. As soon as the portion of thehook at the-end of the slot 21a contacts the pin 23a, the hook dropsdown and engages one of the links of chain 5. "The sudden shockencountered thereby is relievedby means of the piston Biawhich movesforward rapidly compressing the air trapped in the cylinder 39a whichescapes slowly through the needle valve Ma. When the piston reaches theend of its stroke, the carriage secured to the ends of the tubes bymeans of jaws "a then moves forward with-the chain 4. The spring 52acompressed by this action returns the piston 88a to its normal idleposition when the tubes have passed through the die, thereby permittingthe jaws I la to open by the action of compressed springs 22a to releasethe opposite ends of the tubes therefrom.

carriage from the rear end of the return track to blank-grippingposition in front of the die.

3.' A draw bench comprising a blank-gripping carriage adapted to bepositioned in front of a die, means for detachably engaging the carriageto move it with a gripped blank forward away from the die to a positionat which the blank is released from the die and carriage, a return trackbelow said means, down which the released carriage travels forward fromsaid carriage-engagingmeans, means for lowering the rear end of thetransfer track so that said carriage travels back ac ss it-and onto saidreturn track, and means to elevating the carriage from the rear end ofthe return track to blank-gripping position in front of the die.

4. A draw bench comprising a blank-gripping.

carriage adapted to be positioned in frontof a die, means for detachabiyengaging the carriage to move it with a gripped blank forward away fromthe die to a position at which the blank is released from die andcarriage, a return track below said means, an inclined transfer trackdown which the released carriage travels-forward from saidcarriage-engaging means, the front end of the transfer track beingpivoted on a horizontal axis, means for raising and lowering the rearend of the transfer track to cause it to register with saidcarriage-engaging means and said return track, and means for elevatingthe carriage from the rear end of the return track to blank-grippingposition .in. front of the die.

Although this invention has been described in connection with thedrawing of tubes, it will be clear that it is equally applicable to thedrawing of rods and other shapes.

According to the provisions of the patent statutes, we have explainedthe principle and construction of our invention and have illustrated anddescribed what wenow consider to represent its best embodiment. However,we desire to have it understood that, within the scope of the appendedclaims, the invention may be practiced otherwise than as specificallyillustrated and described. t

We claim: I

1. A draw bench comprising -a blank-gripping carriageadapted to bepositioned in front of a die, a traveling endless chain for detachablyengaging the carriage to pull it with a gripped blank forward away fromthe die to a position at which the blank is released from the die andcarriage, means for\ returning the released carriage to blank-grippingposition in front of the die and including a' track inclined downwardlyfrom the front end of said chain, and means depending from the bottom ofthe carriage adapted to be engaged by the chain to push the car ontosaid track.

2. A draw bench comprising a blank-gripping carriage adapted to bepositioned in front of a die, means for detachably engaging the carriageto move it with 'a gripped blank forward away from the die to a trackinclined downwardly 5. A draw bench comprisinga blank-gripping carriageadapted to be positioned in front of a die, to move it with a grippedblank forward away from the die to a position released from the die andcarriage, a return said means, means for transferring the releasedcarriage from said carriageeengaging means to the front end of thetrack, a removable stop associated with said track to arrest thecarriage before it reaches the lower end of the track, and

" means for 'elevating the carriage from the rear end of the track toblank-gripping position in front of the die.

' 6. A draw bench comprising a blank-gripping carriage adapted to bedie, means for detachably engaging the carriage to move it with agripped blank forward away released from the die and carriage, anelevator below the die adapted to raise a carriage to from the die% aposition at which the blank is released from the die and carriage, agravity return track inclined downwardlyrand rearwardly below saidmeans, an intlined transfer track down which the released carriagetravels from said carriage-engaging means to the front end of saidreturn track, and means for elevating the blank-gripping position infront of the die, a gravity return track below said means extendingdownwardly and rearwardly-to the elevator, and

means for transferring the released carriage fromleased. means adjacentthe die. for pushing said hook forward for engagement by saidfirst-mentioned means, means for moving said hook back into the carriage'after the carriage is released from said carriage-moving means,meansfor returning the released carriage to a position below the die,and means 1 for elevating the. carriage with its retracted hook toblank-slipping position in front oi the die.

an inclined transfer track means for detachably engaging the carriage atwhich the blank is and rearwardly belowpositioned in front of a positionat which the blank is 8. Adraw bench comprising a blank-grippingcarriage adapted to be positioned in front of a die, clamping jawsmounted on said carriage for gripping the ends of a blank projectingfrom the die, means for detachably engaging the carriage to move it witha gripped blank forward away from the die, a counterweight operativelyconnected to said jaws and biasing them forward, for automaticallyreleasing the jaws from the blank when the blank leaves the die, meansfor returning the released carriage to a position in the vicinity of thedie, and means for moving the returned carriage to blank-grippingposition in front of the die.

'9. A draw bench comprising a blank-gripping carriage adapted to bepositioned in front of a die, clamping jaws mounted on said -carriage, asliding hook mounted in the carriage and adapted when pulled forward tohold said jaws tightly clamped on a blank, means in front of thecarriage for detachably engaging said hook to move the carriage with agripped blank forward away from the die, counterweighted meansoperatively connected to said laws for automatically releasing them fromthe blank when the blank leaves the die, and means for returning thereleased carriage to blank-gripping position in front of the die.

10. A draw bench comprising a plurality of independent carriages adaptedto be positioned in front of a plurality of pairs of blank-reducing diesdisposed at different levels, two laterally spaced sets of clamping jawsmounted on each carriage for gripping a pair of blanks, the jaws on eachcarriage being at a different level than those on the adjacentcarriages, means for detachably engaging the carriages in succession tosuccessively move each carriage with its gripped blanks forward awayfrom the dies to a position where the blanks are-released from the diesand carriages, means for returning the released carriages in successionto a position in the vicinity of the-dies, andmeans for successivelymoving each returned carriage to blank-gripping position in front of thedies.

11. A draw bench compi-isin'g a blank-gripping carriage adapted to bepositioned in front of a die, a pair of horizontally acting clampingjaws mounted on said carriage for gripp the end of a blank projectingfrom the front of the die, said jaws being free of any obstruction abovethe. space between them, means for detachably engaging the carriage tomove it with a gripped blank forward away from the die to a position atwhich the blank is released from the die and carriage, means forreturning the released carriage to a position below the die, and meansfor elevating the returned carriage to blank-gripping position in frontof the die. 4

' 12. A draw bench comprising a blank-gripping carriage adapted to bepositioned in front of a die, a forwardly sliding hook mounted in thecarriage, means in front of the carriage for moving it with a grippedblank forward away from the die to a position at which the blank isreleased. means adjacent the die for pushing said hook forward forengagement by said first-mentioned means, means for holding the carriagestationary 13. A draw bench comprising a blank-gripping die. a forwardlysliding hook mounted'in the carriage, means in front of the carriage formoving it with a gripped blank forward away from the die to a positionat which the blank is released, means adjacent the die for pushing saidhook forward for engagement by said flrst-mentioned means, means forholding the carriage stationary while said hook is being pushed forwardtherein, means mounted on said carriage for absorbing the shockencountered 'by said hook when engaging said first-mentioned means,means for returning the released carriage to a position in the vicinityof the die, and means for moving the returned carriage to blank-grippingposition in front of the die.

' 14. A draw bench comprising a carriage having independently operableblank-gripping means mounted thereon adapted to be positioned in frontof a die, a forwardly sliding hook mounted in the carriage, means infront of the carriage for moving it with a gripped blank forward awayfrom the die to a position at which the blank is released, meansadjacent the die for pushing said hook forward for engagement by saidsecondmentioned means, means for holding the 'carriage stationary whilesaid hook' is being pushed forward therein, means for returning thereleased carriagevto a position in the vicinity of the die, and meansfor moving the returned carriage to blank-gripping position in front ofthe die.

' 15. A draw bench comprising a carriage having independently operableblank-gripping means mounted thereon adapted to be positioned in frontof a die, a hook slidably mounted in the carriage, means in front of thecarriage for moving it with a gripped blank forward away from while saidhookis being pushed forward therein,

carriage adapted to be positioned in front of a the die to a position atwhich the blank is released, means adjacent the die for pushing saidhook forward for engagement by said secondmentioned means, means forholding the carriage stationary while said hook is being pushed forwardtherein, means on said carriage for absorb ing the shock encountered bysaid hook when engaging said second-mentioned means,'means for returningthe released carrlageto a position in the vicinity of the die, and meansfor moving the returned carriage to blank-"gripping position in front ofthe die.

16. A draw bench comprising a plurality of independent carriages adaptedto be successively positioned in front of a group of dies, means on,

the carriages wfor gripping the front ends of blanks projecting throughthe dies, means for detachably engaging the carriages to move aplurality of them in succession forward away from the dies along thesame path at the same time to a position where the blanks are releasedfrom the dies and carriages, the gripping means on each carriage beingin a different position relative thereto than the gripping means on thefollowing carriage so that a plurality of carriages can draw blanksthrough the dies at the same time and thus maintain continuous drawing,and means for returning the released carriages in succession toblank-gripping-positionin front of the dies.

17. A draw bench comprising a plurality of independent carriages adaptedto be successively positioned in front of a group of dies, means on thecarriages for gripping the front ends of blanks projecting through thedies, one track in front of the dies for all of the carriages, anendless chain traveling along the track, means for detachably connectingeach carriage to the chain lowing carriage so that 'a to blank-grippingposition in front oi the dies.

18. A draw bench comprising a plurality of independent carriages'adaptedto be successively positioned in front of a group of dies, means. on thecarriages for gripping the front ends of blanks proiecting through thedies, meansfor detachably engaging the carriages to move a plurality ofthem in succession forward away from the dies along the same path at thesame time to a position where the blanks are released from the dies andcarriages, the gripping means on each carriage being in a differentposition relative thereto than the gripping means on the folplurali-tyof carriages can draw blanks throuah the dies at the same time and thusmaintain continuous drawing,

a l means for returning the released carriages by I gravity insuccession to a position below the dies, and means for elevating thereturned carriages in succession to blank-gripping position in front ofthe dies. I

19. 'A draw bench comprising a plurality of independent carriagesadapted to be positioned in front of a plurality of blank-reducing diesdisposed at different levels and at diiferent lateral positions, a setof clamping jaws mounted on each carriage for, gripping a blank, theJaws on each carriagebeing at a different level and a different lateralposition than those on the adjacent car- 'riages, one track in front ofthe dies for all of the carriages, means for detachably engaging thecarriages in succession to successively move each carriage withitsgripped blank forward along said track away from the'dies to a positionwhere the blank is released from the dies and carriage and means forreturning the released carriages in succession to blank-gripping Yposition in front of the dies;

EARL kNUnsEN. HOWARD H. TALBOT.

